server-identifier hostname;

The server-identifier statement can be used to define the value that is sent in the DHCP Server Identifier option for a given scope. The value specified must be an IP address for the DHCP server, and it must be reachable by all clients served by a particular scope.

The use of the server-identifier statement is not recommended - the only reason to use it is to force a value other than the default value to be sent on occasions where the default value would be incorrect. The default value is the first IP address associated with the physical network interface on which the request arrived.

The usual case where the server-identifier statement needs to be sent is when a physical interface has more than one IP address, and the one being sent by default isn't appropriate for some or all clients served by that interface. Another common case is when an alias is defined for the purpose of having a consistent IP address for the DHCP server, and it is desired that the clients use this IP address when contacting the server.

Supplying a value for the dhcp-server-identifier option is equivalent to using the server-identifier statement.